Correctness
Spelling, grammar and punctuation.
Me and PriyaPriya and Ithe results isthe results aretommorowtomorrow
Writing help that never leaves your computer.
Oppenly underlines spelling, grammar, clarity and tone problems as you type on almost any website, and fixes them in one click. It runs entirely in your browser. Free and open source.
- No account
- No tracking
- Works offline
Four kinds of suggestions
The same categories you may know from other writing assistants, each with its own colour. These examples come straight from Oppenly’s checks.
Clarity
Wordy phrases, passive voice and hard-to-read sentences.
in order totomake a decisiondecideThe report was written by the teamThe team wrote the report
Engagement
Bland, overused and repeated words.
really goodexcellentvery importantcrucialvery badterrible
Delivery
Tone, confidence and politeness, tuned to your goals.
Sorry for the late replyThank you for your patienceI was wondering if you couldCould youHey guysHi everyone
Every suggestion in one place
Click the Oppenly button in the corner of a text box to see all suggestions for it. Accept every spelling and grammar fix at once, or go through them one by one. The Insights tab shows the tone of your text, reading time and an overall score.
Rewrite a sentence
Select text to shorten it or make it more formal, friendlier or more confident. These rewrites run on your device. Connect an AI provider to add options like “improve”, “expand” and your own instructions.
Off when you want it off
Pause Oppenly for an hour, turn it off on one site or everywhere, straight from the button in the text box. It stays out of code editors and password fields.
Your writing stays yours
Most writing assistants send everything you type to their servers. Oppenly doesn’t have servers.
Checked on your device
The grammar engine and Oppenly’s style rules run inside your browser. Your text is never sent anywhere to be checked.
No account, no analytics
There is nothing to sign up for. Oppenly collects no usage data, sets no cookies and shows no ads.
AI only if you ask for it
Connect an AI provider with your own key, or a model on your computer. Oppenly asks for your consent first and sends text only to the provider you chose.
Open source
All of the code is public under the Apache 2.0 license, so anyone can check these claims.
Use the AI you already pay for
Oppenly works without AI. When you want context-aware suggestions and full rewrites, pick a provider and paste your key. There is no prompt limit: you pay the provider for what you use, or nothing if the model runs on your computer.
- OpenAI
- Anthropic
- Google Gemini
- xAI
- Mistral AI
- DeepSeek
- Groq
- Cerebras
- OpenRouter
- Together AI
- Fireworks AI
- Perplexity
- Cohere
- Azure OpenAI
- Amazon Bedrock
- Moonshot AI
- Alibaba Qwen
- Chrome built-in AI
- Ollama
- LM Studio
- llama.cpp
Plus any server compatible with the OpenAI, Anthropic or Gemini APIs. Providers in blue run on your computer.
A full editor, on your machine
The Oppenly web app is a document editor with the same checks, plus goals, performance stats, formatting, and Word, OpenDocument and Markdown import and export. It runs from the source code on your own computer and keeps documents in your browser.
Run it
Needs Node.js 20 or later and
pnpm. Then open
http://localhost:4870.
git clone https://github.com/shivashis-adhikari/Oppenly.git
cd Oppenly
pnpm install
pnpm webHow Oppenly compares with Grammarly
Grammarly does more in some places: it checks for plagiarism and works in desktop apps and Google Docs. Here is where the two differ most.
| Feature | Oppenly | Grammarly Free | Grammarly Pro |
|---|---|---|---|
| Price | Free | Free | $12 a month billed yearly, or $30 monthly |
| Account needed | No | Yes | Yes |
| Where your text is checked | On your device | On Grammarly’s servers | On Grammarly’s servers |
| AI prompts | No limit, with your own provider | 100 a month | 2,000 a month |
| Choose your AI model, or run one locally | Yes | No | No |
| Source code | Public (Apache 2.0) | Closed | Closed |
Grammarly details are from its public plan information as of September 2026 and may change. Grammarly is a trademark of its owner. Oppenly is an independent project and is not affiliated with or endorsed by Grammarly.
Questions
Is Oppenly really free?
Yes. There is no paid plan, no ads and nothing to sell. If you connect a cloud AI provider, that provider bills you directly for what you use.
Does it work offline?
Yes. Checking and the built-in rewrites work without an internet connection. Only cloud AI providers need one.
Where does it work?
In text boxes and rich-text editors on most websites: email, social media, chat, forms and content tools. It does not work in Google Docs yet, because Google Docs draws text in its own way and only allows approved extensions to read documents.
Which languages does it check?
English, in American, British, Canadian, Australian or Indian spelling.
What does an AI provider receive?
Only the text you check or rewrite and instructions for the task, sent with your key to the address you set up. Nothing else from the page or your browser. You can remove a provider at any time.
Which browsers are supported?
Chrome, and browsers built on it such as Microsoft Edge and Brave. The web app runs in any modern browser.